Subscription to AAR Circular Letters

AAR Circular Letters are the primary method of communication between the AAR and the industry, including announcement of new or amended standards and rules. To ensure compliance to the latest AAR standards, AAR Circular Letters must be monitored. The AAR Circular Letter System emails notices to all subscribers. Circulars are a fee-based service provided by Transportation Technology Center Inc. in Pueblo, Colorado. Once subscribed, access the circulars at: https://www.aar.org/circulars